MDM192 MULTI-DROPS DIGITAL MODEM FOR PRIVATE LINE. USER GUIDE Document reference :

Transcription

1 MDM192 MULTI-DROPS DIGITAL MODEM FOR PRIVATE LINE USER GUIDE Document reference :

2 If you have questions about the MDM192 or desire assistance, contact ETIC TELECOMMUNICATIONS at the following address : ETIC TELECOMMUNICATIONS 13 Chemin du vieux chêne MEYLAN FRANCE TEL : FAX : [email protected] web : This user guide applies to the following product references with the manufacturing index 07 MDM192-0 MDM192-1 Modem designed for 9 to 40 VDC supply voltage Modem designed for 40 to 60 VDC supply voltage Page 2 USER GUIDE ref MDM192

3 CONTENTS 1. PRODUCT OVERVIEW NETWORK TOPOLOGIES MODEM PERFORMANCE Line characteristics Number of modems that can be connected to a line Range DESCRIPTION Leds DIP switches Connectors INSTALLATION Setting the data rate and the byte frame Matching the modem to the transmission line RS232 local interface RS485 / RS422 local interface Connection to the line : Point to point Connection to the line : Multidrop Test Frame MDM192 USER GUIDE ref Page 3

4 Page 4 USER GUIDE ref MDM192

5 1. Product overview The MDM192 modem provides half-duplex data transmission between PLCs (for instance), on a 2 wires cable over up to 30 Km. Point to point or multi-drops transmission 16 PLCs (and even more) can be connected to the same line. (2 wires twisted and shielded pair) at a data rate up to b/s. Reliability The modems are connected in parallel to the line. If one modem fails, it does not prevent the rest of the network from transmitting normally. Line isolation The modem is isolated from the line through a 4000 VRMS transformer. Local interface The modem provides an RS232, RS422 and RS485 asynchronous interface. The data rate ranges from 1200 to b/s (7 or 8 bits with or without parity, 1 start bit, 1 or 2 stop bits). Transmission delay time The digital technique used provides a very low delay of transmission (only 3 characters time). Compatibility The MDM 192 is able to transmit most PLC protocols among which : Rockwell : Siemens : Schneider Electric : Omron : DF1, DH485 PROFIBUS DP MODBUS, UNITELWAY SYSMACWAY... and generally speaking any master / slave asynchronous protocol. MDM192 USER GUIDE ref Page 5

6 2. Network topologies Point to point Bus Star Page 6 USER GUIDE ref MDM192

7 3. Modem performance 3.1. Line characteristics The MDM 192 is designed to be connected to any 2 wires line; even if its diameter is very large or very small, and even if it is a coaxial cable. However, the performance of the product is the best when it is connected to a twisted shielded pair Number of modems that can be connected to a line Up to 16 modems can be connected to the same line. See table 1 below. If more than 16 modems have to be connected to the line, it will work properly but the range performance (whole length of the line) will decrease Range The range (whole length of the line) depends upon the data rate, the line quality and the number of modems connected to the line. If the line is noisy, the performances may decrease. To increase the range, it is possible to repeat the data using the following design : Repeater RS485 MDM192 USER GUIDE ref Page 7

8 TABLE 1 : Range Range with 2 modems connected to the line Cable diameter in mm (50 nf / km) Data rate 0,4 0,5 0,6 0, b/s 13 km 16 km 20 km 26 km 34 km 2400 b/s 13 km 16 km 20 km 26 km 34 km 4800 b/s 13 km 16 km 20 km 26 km 34 km 9600 b/s 10 km 12 km 15 km 20 km 25 km b/s 6 km 7 km 9 km 12 km 15 km Range with 8 modems connected to the line Cable diameter in mm (50 nf / km) Data rate 0,4 0,5 0,6 0, b/s 12 km 14 km 18 km 24 km 29 km 2400 b/s 12 km 14 km 18 km 24 km 29 km 4800 b/s 12 km 14 km 18 km 24 km 29 km 9600 b/s 9 km 11 km 13 km 18 km 22 km b/s 5 km 6 km 7 km 10 km 12 km Range with 16 modems connected to the line Cable diameter in mm (50 nf / km) Data rate 0,4 0,5 0,6 0, b/s 11 km 13 km 16 km 22 km 26 km 2400 b/s 11 km 13 km 16 km 22 km 26 km 4800 b/s 11 km 13 km 16 km 22 km 26 km 9600 b/s 7 km 9 km 11 km 15 km 18 km b/s 4 km 5 km 6 km 9 km 11 km Page 8 USER GUIDE ref MDM192

9 4. Description MDM192 Up to evolution index 8 MDM192 From evolution index Leds RD TD Data reception from the line Data transmission to the line Data reception errors Test frame transmission (if SW1-8 is ON) The led is blinking Power supply MDM192 USER GUIDE ref Page 9

10 4.2. DIP switches TABLE 2 SW1 DIP SWITCHES (8 positions) FRAME SW1-1 1 byte = 10 bits OFF 8 b + start + 1 stop 7 b + parity + start + 1 stop 7 b + start + 2 stops 1 byte = 11 bits ON 8 b + parity + start + 1 stop 7 b + parity + start + 2 stops DATA RATE SW1-2 SW1-3 SW b/s For compatibility with evolution 01 to 06 OFF OFF OFF b/s Normal position OFF OFF ON b/s For compatibility with evolution 01 to 06 OFF ON OFF b/s Normal position OFF ON ON b/s For compatibility with evolution 01 to 06 ON OFF OFF b/s Normal position ON OFF ON 2400 b/s ON ON OFF 1200 b/s ON ON ON Reserved SW1-4 SW1-5 SW1-6 Mandatory OFF OFF OFF TEST Test Frame transmission Normal operation SW1-8 ON OFF Page 10 USER GUIDE ref MDM192

11 TABLE 3 : SW2 DIP SWITCHES Adapting the modem to the line quality, if necessary From the 9 evolution index only Line impedance Output R SW2-1 SW2-2 > Ohm OFF OFF Default position 270 < Zc < Ohm ON OFF 190 < Zc < Ohm OFF ON Zc < Ohm ON ON TABLE 4 : SW3 DIP SWITCHES Selecting the value of the line matching Resistor From the 9 evolution index only Line impedance Matching R SW3-1 SW3-2 > Ohm OFF OFF Default position 270 < Zc < Ohm ON OFF 190 < Zc < Ohm OFF ON Zc < Ohm ON ON Any modification of the dip switches position operates immediately. MDM192 USER GUIDE ref Page 11

12 4.3. Connectors TABLE 5 : 10 points screw block Line and local RS485 and RS422 interface Pin Nr Signal Function Line 1 L1 Line signal wire 1 2 L2 Line signal wire 2 3 Adp Line adaptation bridging points 2 and NC 5 - NC 6 - NC Local RS485 and RS422 interface 7 RS422 B RS422 Transmission polarity B (to MDM192) 8 RS422 A RS422 Transmission polarity A (to MDM192) 9 RS485 B RS422 Reception polarity B (to the local data terminal) or RS485 polarity B 10 RS485 A RS422 Reception polarity A (to the local data terminal) or RS485 polarity A TABLE 6 : DB9 fem. RS232 CONNECTOR Not isolated local Interface Pin Nr Circuits Designation Terminal-Modem 1 CD 109 Carrier detect 2 RX 104 Data reception 3 TX 103 Data emission 4 DTR 108 Data terminal ready 5 SG 102 Signal ground 6 DSR 107 Data set ready 7 RTS 105 Request to send 8 CTS 106 Clear to send 9 RI 125 Ring indicator TABLE 7 : 2 pins screw-block Supply voltage!! CHECK THE PRODUCT REFERENCE ON THE RIGHT SIDE OF THE PRODUCT Pin Nr Signal Function to 40 VDC supply voltage for reference MDM to 60 VDC supply voltage for reference MDM Signal ground Page 12 USER GUIDE ref MDM192

13 5. Installation 5.1. Setting the data rate and the byte frame The MDM192 modem does not adapt the data rate between the line and the serial interface (RS232 or RS485 or RS422); it transmits at the same data rate over the line and over the serial interface. Byte frame The switch Nr 1 of the SW1 block must be set OFF or ON according to the number of bits of each byte (10 or 11 bits); see table 2. Data rate The switches Nr 2 and 3 and 7 of the SW1 block must be set in the position corresponding to the data rate in use. MDM192 USER GUIDE ref Page 13

14 5.2. Matching the modem to the transmission line This paragraph applies to the products the evolution index of which is 9 or higher (see the identification label on the side of the product). It describes how to adapt the modem to the characteristics of the line, using the SW2 and SW3 switches blocks, to get the best possible transmission distance. The SW2 and SW3 swiches blocks are located on the side of the product. The products the evolution index of which is 9 or higher, are fully compatible with older products (index 8 or lower); in that case, all the switches of the SW2 and SW3 switches bocks (on the side of the product) have to be left OFF. Principle The SW2 and SW3 switches blocks have to be set according to the characteristics of the line represented by the line impedance (Zc). The line impedance Zc can be calculated as follows : Zc = square root [2 X R/Cω] with R= Wire resistance (Ohm / Km) C = Mutual capacitance between the wires (Farad / Km) ω = Signal pulsation (6,28 x F) To avoid calculations, refer to table 8 just below. TABLE 8 : Line impedance / wire diameter and cable mutual capacitance Wire diameter mm 0,4 0,4 0,6 0,6 0,8 0,8 1 1 Mutual capacity nf/ km Zc at 1200 or 2400 or 4800 b/s Zc at 9600 b/s Zc at b/s SW2 and SW3 switches blocks setting All the modems connected to the same line have to be set identically. Set the switches according to the table 9 below. TABLE 9 : SW2 and SW3 setting Line impedance Output R Value of the matching R Ohm SW 2-1 Sw2-2 SW3-1 SW3-2 >350 OFF OFF OFF OFF 270 < Zc < 350 ON OFF ON OFF 190 < Zc < 270 OFF ON OFF ON Zc < 190 ON ON ON ON Page 14 USER GUIDE ref MDM192

15 5.3. RS232 local interface The RS232 interface is available on the DB9 connector on the front panel. The data terminal must be less than 10 meters far from the modem. The connection to a PC is achieved with a straight cable ( 1 to 1, 2 to 2 etc ) 5.4. RS485 / RS422 local interface The RS422 and RS485 interfaces are available on the 10 pts screw block. Up to 16 data terminals can be connected to the local RS485 bus. The data terminals must be less than 100 meters far from the modem. - RS485 / RS422 polarization The MDM 192 includes line polarization resistors. - RS485 / RS422 line adaptation For a several meters long connection over the RS485 local interface, it is not necessary to adapt the RS485 line. For longer distances, connect a 120 Ohm resistor at each end of the line. MDM192 USER GUIDE ref Page 15

16 5.5. Connection to the line : Point to point Line connection The line has to be connected to the 10 points screw block points 1 and 2 The wires can be inverted. The MDM192 includes the line adaptation resistor. It has to be brought into service at each end of the line by bridging points 2 and 3 of the 10 pins screw block Shield If the cable is shielded, the shield must be connected to the protective earth pin available at the bottom of the product. Page 16 USER GUIDE ref MDM192

17 5.6. Connection to the line : Multidrop Connecting to the line the modems located at each end (modems 1 and 5 of the drawing above) : The 2 wires of the line have to be connected to the 10 points screw block points 1 and 2. The wires can be inverted. The MDM192 includes the line adaptation resistor. It has to be brought into service in each modem located at the end of the line by bridging points 2 and 3 of the 10 pins screw block Shield : If the cable is shielded, the shield must be connected to the protective earth pin available at the bottom of the product. MDM192 USER GUIDE ref Page 17

18 Connecting to the line a modem not located at the end of the line (modems 2 to 4 of the drawing above) : The 2 wires of the line have to be connected to the points 1 and 2 of the 10 points screw block The wires can be inverted. Line Line 10 pts screw block MDM192 Nr 1 2 L1 L2 Shield If the cable is shielded, the shield must be connected to the protective earth pin available at the bottom of the product Test Frame For test purposes, the MDM 192 is able to transmit permanently a character frame. That function is available only if the data rate is set at a value from 4800 to b/s. To enable the test function, set to ON the switch Nr8 of the SW1 switches block (SW1-8) located on the front side of the product. The red led blinks each time a test frame is transmitted. The test frame is transmitted at the data rate which has been set, but any case with 1 stop and no parity (8N1). The frame can be displayed with a PC using the ModemView software (Copyright ETIC), or any terminal emulation software. Page 18 USER GUIDE ref MDM192

19 Local Interface Data Range (informative value) Configuration Size Isolation from the line EMC Security Thunder Supply voltage Power consumption Operating T CARACTERISTICS RS485 - RS422 - RS232 Asynchronous : 7 or 8 bits Parity : none / even / odd 1 start, 1 or 2 stops b/s Up to 30 Km 8 DIPswitches 115 x 38 x 96 mm (h, l, p) Transformer : 4000 Vrms EN EN EN et -5 9 to 40 VDC reference MDM to 57 VDC reference MDM ma - 24 VDC -20 C / + 60 C (dry air) MDM192 USER GUIDE ref Page 19

20 13, Chemin du Vieux Chêne Meylan France Tél : Fax : [email protected] Web :